Safety centrifugal percussion base fuse



H. MEREDITH-IONES.

SAFETY CENTRIFUGAL PERCUSSION BASE FUSE.

APPLICATION FILED JVUNE I3, 1917.

1,336,701. Patented Apr. 13, 1920.

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' SAFETY onnrairoeanrnacussioiv Bass rusa.

To all whom t may concern l Be it known that HUBERT Mnnnorrri- JONES, a subject of the Kingof Great Britain, and resident of New Yorlnll. Y., have invented certain new and useful. Improvements in Safety Centrifugal vPercussion Base Fuses, of which the -following is' a specification.

My invention relates to safety fuses for shells and concerns particularly a percussion base fuse. 'A

rlhe invention consists in the features7 combination and Varrangement of'parts hereinafter described andparticularly pointed out inthe claims.. Y

1n the accompanying drawings Figure 1 is a sectional view of the fuse.

Fig. 2 is a plan view. Y I

Fig. 3 is a side view of the screw cap.

Fig. 4L is a bottoni plan view ofthe screw cap. i A

Fig. 5 is anelevation of the inside face of one of the sections of the primer cage.

Fig. 6 is a plan view` of thepart shown in Fig. 5. Y w

Fig. 7 is a side view of the check thimble.

Fig. .S is a plan view of the check thimble.

Fig. 9. is a plan view of the primer cup.

p Fig. 10 isa sectional view of the primer cup. y V I Fig. 11 is a plan view of the'primer plate.

Fig. 12 is a plan view of a clip spring.

Fig. T13 is a sectional view of another form of thefuse. y

Fig.. 1-1 is a view ofa dierent form of Y 1n these drawings-1 indicates the fuse body having a screw-threaded Aportion adapted to screw threads in the base ofthe shell and having a head 15, which provided with openings 16 to vreceive al wrench;

rllhis body or shell at its inner end isscrewthreaded internally. and receives' acap 17 which is screw-threaded to .fit the interior screw threads on the body or shelhsaid cap having a shoulder at 18 resting against the edge 4of the casing or body. lVithin the casing is mounteda primer cage .consisting of two members`l9 Vgenerally ofV semi-circu-I lar form, each member having a recess or chamber therein at 2O and each having a neck 21 with a recess 22 therein. These members `of the primer cage are' heldfto-V gether yieldingly by springclips 23, there being two of these clips vfitted to the same groove formed in the outer side of the members of the primer cage. These clips are Specification or" Letters Patent.

' rammed Apr. is, ieee.

. Application led June 13, 1917. Serial No. 174,590.

formed with lugs lwhich fit into openings in the parts of the cage, one of which openings is indicated at 23a. Within the primer cage a primer lcup 24: is arranged, this consisting of a thin shell having a drawn or swaged projection 25 on its interior. This cup contains the primer material and itsV inner side is covered by a primer plate 26. rI`he neck portion of the primer cage receives the firing pin 27 which is formed integrally with the screw cap or may be formed separately therefrom and secured thereto. This firing pin has a rounded or conical end opposite the primer plate. lThe cage is of smaller diameterA than the interiork of the casing or Amain body of the fuse and it is heldin position with its bottom' portion 28 normally above the bottom of the bodyIA ofthefuse, a spring 29 seated in a pocket of the cage and a pocketin thebottom of the main casing serving to press the cage `normally away fromthe bottom ofthe casing. Surrounding the primer'cage is a check` thimble 30 formed of sheet metal and of cylindrical shape with itsends provided with inwardly turned flanges 31 and 32.

Openings 33 are formed through the screw cap at several points around the center and around the firing pin, these openings leading from the interior of the casing to the outside and a drivepin ,34 carried by the. firing pin and extending transversely thereof has its ends lying between the sectionsof the primer cage. The normal prosition of the parts is indicated in Fig'. 1, from which it willbe noticed that the members of the primerv cage are pressed together by the springclips and the neck of the cage lits closely about the firing pin and the primer cage is held at aslight distance away from the bottom of the body or casing 111. When the shell `is fired from the gun thefirst eect is the movementl of the cage with respect to the body or casingof the fuse and toward the bottom or outer. end thereof7 this action being dueto the inertia of the cage and being permitted by. the spring 29 and also by the sliding fit between the exterior face of the cage and the flanges of the check thimble and it will here be noticed that this check thimble is lprevented from following the movement of the cage'toward the bottom or outer end of the main casing or body,

because the thimble rests on a'shoulder '35.'

opposite the outer or lower fiange 31 of the check thimble and will also bring the shoulder 37 of the cage below the upper flange 32 of the thimble and because of the rapid revolution of the shell and all parts of the fuse due to the rifling of the gun, centrifugal force will be brought into play and the members of the primer cage will fly outwardly away from each other and toward the wall of the main body, this action being permitted because as just stated the groove 36 is now located opposite the lower flange 31 of the thimble and the shoulder 37 is located outside of or below the upper flange 32. The members of the cage having thus separated because of the centrifugal force and because the spring clips yield to permit this action the two members of the cage will be locked in their altered position by the fianges 3l and 32 engaging respectively the wall of the shoulder 37 and the parts will remain in this position during the fiight of the projectile until the impact of the same with the object aimed at takes place at which time the cage will fly forwardly in respect to the casing and the firing pin will then act upon -the primer and ignition will take place and the fire passing out through the openings 33 will be communicated to the explosive in the shell and the explosion will take place.

It may be noted here that when the members of the cage are in normal position, that is held toward each other by the spring clips, the inner or upper end of the neck of the cage members will engage beneath a shoulder 38 adjacent the firing pin but when the membersof the cage are separated these neck portions will stand laterally out beyond the said shoulder or in other Awords out of line therewith, so that no obstruction will be offered by these shoulders to the free forward movement of the cage members.

Furthermore, when the cage members are separated ample space is provided around the firing pin for the passage of the fire from the primer through the neck portions of the cage members alongside the firing pin and thence through ythe openings 33 in the shell.

It may be further pointed out that the thimble 30 while fitting against the inner wall of the casing or body sufiiciently tight to hold the cage members locked in their retracted positions after the said members have set themselves against the bottom of the casing this contact of the thimble with the inner wall of the casing is such that the thimble can be carried forward with the members ofthe cage when this fiies forwardly as a resultl of the shell striking the object aimed at.

Itwillbe seen from the above that normally the cage is-in the condition and in the position illustrated in Fig. 1, that is, its

groove 36 and the4 members are closed and are held in advance of or away from the bottomV of the casing and when the projectile is fired from the gun the cage sets itself against the bottom of the body of the fuse where it is locked by engagement with the thimble, the parts of the cage having vseparated under the centrifugal force and the next action takes place when the impact of the projectile against the object aimed at occurs, whereupon the cage will fly forwardly and cause the primer to be thrown into contact with the firing pin, resulting in the firing of the charge, as above set forth.

I show in Fig. 13 a modification of the invention in which the parts of the cage are held by two sets of spring clips 23 and in this form also the screw cap is-not employed and the firing pin is supported independently of the body or casin of the fuse, thisV figure illustrating the act that my invention may be embodied in different forms while adhering to the underlying principles involved in the invention. f

Briefly stated the cycle of operation involved in this invention is (first) the axial movement of the cage members toward the bottom or `outer end of the fuse body; (next) their radial separation and their retention in this axially and radially displaced position by means of the thimble and the centrifugal force arising from the action of the rifiing, keeping the parts out in contact with the thimble, and (finally) the forward axial movement or the cage members while remaining radially separated and thereby the striking of the primer against the firing pin.

In Fig. 14 I illustrate the fact that theV invention may be embodied in a form in which the primer 24X instead of being mounted in the cage or carrier is mounted in a recess in the head of the casing. The carrier of sectional form shown at 19X has the firing pin mounted thereon, this firing pin being divided longitudinally with one of its members mounted on the sections of the carrier. with extensions 19a normally restin against stopsA or shoulders 38X of the head o the casing adjacent whichk are openings or recesses 38 to receive the extensions 19 when the carrier is separated radially and is moved forward. The locking thimble is substantially like that first described, this being indicated at 30X and the carrier is grooved at 36X and has the shoulder 2lX substantiallyv as in the first form. The operation of the The carrier also is provided device is substantially the same as that in the form first described, the firing pin, however, moving to and vcontacting with the primer, which is fixed in the casing instead of the primer moving with the carrier to contact witha fixed firing pin.

If desired the sectional firing pin may be provided a cap member. l

Reverting to the primer plate 26 of Fig. ll it will be understood Vthat the cross form of this plate provides spaces or openings for the flashing of the exploded primer therethrough.

What I claim is 1. In combination in a safety fuse for projectiles, a casing, a primer carrier or cage composed of radially separable members, said cage being axiallyfmovable within the casing and normally held in a forward position in said casing and adapted to assume a position away fromits normal location and toward the outer end of the casing due to the firing of the projectile from the gun, means for-locking the cage in its outer position, said locking means engaging the members of 'the cage when they are displaced radially, due to centrifugal force, said cage kwith its locking' means moving forwardly under the V`force of the impact when the projectile strikes vthe object and a firing pin to engage the primer when the cage moves forward with its members separated, substantially as described.

2. In combination in a safety percussion base fuse, a firing pin, primer, a carrier for one of said parts, and a casing, said carrier being normally located at an intermediate point in the casingand slidable both rearwardly and forwardly, and being` formed in sections, said carrier having the following cycle of movements due to 'the ringof the projectile, the kcentrifugal force derived from the rifling and the impact of the projectile, respectively, namely iirst an axial movement rearwardly in respect tothe casingpa separating movement of its members radially and finally a forwardV movement, the latter movement causing the primer to be exploded by the firing pin, substantially as described.

3. In combination in a safety fuse, a firing pin, a primer, a sectional carrier or cage.

normally held in forward position relative to the casing, and carrying one of said p ar-ts, a casing, a locking member having'frictional contact with the wall of the casing and` adapted to engage and temporarily hold the members'of the cage against forward movement along the casing, moved rearwardly in respect to the casing and when after b'eing moved radially Vin respect to each other,

said locking means being slidable along the wall of the casing with the cage'when the same moves forwardly due to theimpact, allowing the firing pin to engage the primer when the cage Vmoves forwardly, substantially as described.

'4. In ycombination in a safety fuse, a 'firing pin, avprimer, a sectional carrier within the same normally held in forward position .in respect thereto, and carrying one of said parts, a casing, a thimble having means to engage the membersof the cage when they move rearwardly inrespect to the casing and radially in respect toV each other, said thimble being slidable on the wall of the casing when the cage moves forwardly due to the impact, said firing pin engaging the primer when the cage moves forwardly, substantially as described.'

5. In combination in a safety fuse for projectiles, a primer, a firing pin, a carrier for one of said parts composed of radially separable sections, acasing, said carrier being adapted to have axial movement in respect tothe casing, a thimble'having a flange and seated against the wall of the casing, said flange' engaging a portion of the sections. of the carrier when said carrier moves rearwardly from normal position in respect to the casing and its sections separate radially, said thimble being slidable forwardly with the cage under the impact of the projectile striking the object causing the firingl pin to engage the primer, substantially as described.

6.V In combination 'a casing having ashoulder therein, a thimble seated Aagainst said shoulder and bearingon the inner wallv of the casing'to slide thereon, a carrier normally disposed in a forward position relative to thecasing and composed of radially separable sections, said thimble having 'a -portion to engage and temporarily holdv the cage when moved rearwardly and separated radially and a firing pin to engage the primer, one of asid parts being carried-K by the carrier when it moves forwardly, said thimble being slidable with the carrier, substantially as described.

7. In combination a casing, acagecomposed of separable sections carrying the primer between them, 'a spring for pressing the cage normally forward in relation to the casing, means for engaging the members of the casing when movedl axially to the rearof the casing and separated in respect to each other to temporarily hold the sectionsin their retracted-positions, sai'd engaging means allowing the cage to move forwardly under the impact of the striking project-ile and a firing pin against which the primer contacts when the cage moves forwardly, substantially kas described.

8. In combination a casing, a sectional primer carrying cage within 'the samel normally disposed in a forward position relative to the casing, means for holding the members Vofthecage in position when moved axially rearward inre's'pect tothe casing and when saidmembers are separated radially,

a `firing pin, the 'said holding means allowl ing the-cage to move forwardly under the impact ofthe striking projectile to bring the primer against thefiring pin, substantially as described. v

9. n combination, a primer, a` firing pin, a sectional' carrier for one of said parts, :a

rs., lli

casing, said carrier being movable axially ofthe casing and with its members adapted to separate radially, a shoulder to limit the lforward position of the carrier when its members are closed toward each other, means to engage and temporarily hold the members of the cage when moved rearwardly in respe'ct to the casing and radially in respect to each other, the said radial movementV of the members removing them from the said shoulder. and placing them in position to move forwardly past said shoulder, said engaging means permitting the cage to move forwardly under the impact causing the -firing pin to impinge against the primer when the carrier moves forwardly, substantially as described. Y

10. In combination a casing, a sectional carrier withinV the casing movable axially thereof and with its members adapted to separate radially, a shoulder to limit the forward position' of the carrier when its members are closed toward each other, means to engage and temporarily hold the members of the carrier when moved rearwardly in respect'to the casing and radially in respect to each other, the said radial movement of the members removing them from the said shoulder and placing them in position to move forwardly past said shoulder, said engaging meansA permitting the carrier to move forwardly under the impact,

Y a primer, and a firing pin against which the primer contacts when the cage moves forwardly, said shoulder for determining the normal position of the cage being on the firing pin, substantially asdescribed.

11. In combination a casing, a sectional carrier within the same having a groove and a shoulder, a firing pin and avprimer one of which is carried by the carrier, a thimble having a ange at each end to engage the groove and shoulder, respectively, said carrier having its members adapted to separate radially and being located normally in Y an intermediate position in respect to said casing, the said thimble temporarily holding the members of the 4carrier when moved rearwardly in respect to the casing and radially outward in respect to each other, and movingwith said carrier under the impact of the striking projectileto bring the firing 'pin and primer together, substantially as described. f

12. In combination a casing, a sectional primer carrying cage within the casing, a spring for pressing the cage forwardly, a iringipin surrounded by a portion of the cage and having a'shoulder to determine the j 'firing pin to explode the primer, substan-l normal intermediate position of the cage in respect to vthe casing, said cage moving rearwardly in respect to said casing when the projectile is fired and its members separating radially by centrifugal force due to the rifling, a thimble having frictional contact with the casing and engaging the members of the` cage when moved axially to their rearward position and separated radially to temporarily ,hold them against forward movement, the separated members of the cage being out of line with the limitin shoulder surrounding the firing pin, thesai cage under the impact and while in sepa-1 ally under centrifugal force, and a firingv pin against which the separated cagercarries` the primer on moving forward due to the impact of the projectile, substantially as described.

14. In combination in a safety fuse for projectiles, a casing, a cage of smaller diameter .than the interior of the casing and composed of radially separableV sections, said casing having a shoulder against which the cage bears to retain it normally in an intermediate position, means for centering said cage within the casing but allowing the cage sections to separatev when it moves to its outward position consequent upon firing the projectile, said cage Ymoving forward under the impact of .the projectile past. the

said shoulder'and a -iring pin and a primer, one of said last mentionedparts being carriedby the cage, substantially as described.

15. In combination in a safety fuse for projectiles, a firing pin member, a primer member, a casing holding one of said members, a carrier for the other of said Ymembers composed of radially separable parts, said carrier being axially movable Within the casing and normally held in a forward position in said casing and adapted to assume a position away from its-normal 1ocation and toward the outer end of the casing dueto the firing of the projectile from l the gun, means for locking the carrier in its outer position, said locking means engaging the members of the carrier, when they are displaced radially, due to centrifugal force, said carrier with its locking means moving forwardly under the force of impact when the projectile strikes the object to. cause the tially as described.

ture.

In testimonywvhereof, I -afllx mysigna-l 

